Friendly fire is a military term which refers to the discharge of a weapon which results in death or injury among fellow soldiers or allies. In some circles, the terms “amicide,” for killing a friend, or “fratricide,” for killing brothers in arms, are preferred to the “friendly fire” euphemism. Friendly fire incidents have been a part of warfare since it began, although the development of more sophisticated and deadly weapons has made the problem regrettably more widespread.

In the military, the definition of friendly fire excludes incidents in which members of the military deliberately fire on their allies or fellow soldiers. The military also does not allow accidental killings into its definition of friendly fire, preferring to restrict it to unforeseen and unintentional injuries and deaths which occur during active engagements with the enemy. All incidents of friendly fire and accidents are investigated, to learn about why they happened and hopefully to prevent similar incidents in the future.

A number of things can lead to friendly fire. One of the most common is miscommunication, which can result in unclear orders or lack of knowledge about troop movements. Adequate communication on the battlefield can sometimes be very challenging, especially in a chaotic environment. Radios, field telephones, and signaling systems are used to address the problem, which becomes much more complicated when multiple forces such as ground troops and aircraft are coordinating an attack. When allied troops are added to the mixture, maintaining lines of communication can be even more difficult, especially if language barriers are being surmounted.

Poor terrain and visibility also contribute to friendly fire. Soldiers are often fighting on land with which they are not familiar. When being fired upon by enemy troops, the direction from which shots are coming can get confusing. The addition of poor weather conditions and combat stress can lead to a friendly fire incident in which a soldier mistakenly believes that he or she is shooting at the enemy. When a leader issues unclear or ambiguous orders, this can also be problematic when combined with conditions which prevent soldiers from using their own judgement.

The exact number of friendly fire incidents which occur during combat is unclear. It can sometimes be difficult to determine whether a soldier has been killed by friend or foe, and soldiers have been known to conceal incidents of friendly fire. Estimates suggest that anywhere between two and 25% of war-related injuries and deaths may be caused by friendly fire. Most militaries provide extensive training to their soldiers to try and prevent the tragedy of friendly fire, which can have an impact on troop morale, mission success, and public image as well as causing death or injury.